A silver-colored metal window lock mechanism designed for use in UPVC windows, featuring an inline gearbox.
Technical drawing illustrating an offset gearbox for a UPVC window lock, showing a red window profile positioned to the left of the locking mechanism. The diagram contrasts the offset gearbox with an inline gearbox for comparison.
Diagram showing two types of UPVC window gearboxes: Offset Gearbox on the left and Inline Gearbox on the right, with red window profiles and labeled parts for comparison.
A silver-colored metal window lock mechanism designed for use in UPVC windows, featuring an inline gearbox.
Technical drawing illustrating an offset gearbox for a UPVC window lock, showing a red window profile positioned to the left of the locking mechanism. The diagram contrasts the offset gearbox with an inline gearbox for comparison.
Diagram showing two types of UPVC window gearboxes: Offset Gearbox on the left and Inline Gearbox on the right, with red window profiles and labeled parts for comparison.
Avocet

UPVC Window Lock - Inline Espag - 250mm – Replacement uPVC Window PartUPVC Window Lock - Inline Espag - 250mm

£6.99 SKU: HS1988
Backset
Backset
Order by 2pm for same-day dispatch
Klarna

Pay in 4 installments of [klarna_payment]

Learn more
Eye visibility icon in black, representing monitoring, visibility, or visual deterrence, displayed on a transparent background.

Same-day dispatch on orders before 2pm

This is the mechanism inside the window frame that is operated by the handle Gearbox is positioned centrally on the rail (inline) Important Measurements

  • Overall length
  • The 'Backset' (20mm, 22mm)
  • Rail Width (Usually 16mm)

Key benefits
  • Inline espag mechanism - modern flush-fit window locking
  • 250mm to 800mm lengths - match your window height
  • Universal direct replacement - fits most uPVC casement windows
Product overview

This is the mechanism inside the window frame that is operated by the handle

Gearbox is positioned centrally on the rail (inline)

Important Measurements

1) Overall length

2) The 'Backset' (20mm, 22mm)

4) Rail Width (Usually 16mm)
Delivery & Returns

How much is delivery?

UK Mainland Delivery is £2.99 on all items no matter how many you order!

Northern Ireland, Scottish Highlands, Channel Islands £6.00.

We do not offer International Delivery (Ireland, France, Spain etc).

When will my order be dispatched?

Orders before 3pm (Monday to Friday) are usually dispatched same day but may take up to 24 hours.

When will I receive my item?

We ship on 2 working day courier. Fully Tracked. Tracking will be emailed on dispatch. 

Special order items such as keyed alike locks will take longer to dispatch. Please refer to product description for lead times. 

I haven't received my item?

Please email us your name, order number and date of purchase.

We prefer email as it allows us time to research and respond.

Returns Information

We operate a 30 day refunds and return policy. 

If you change your mind you must return the product back to us within 30 days of delivery

Please include a copy of your invoice and a note stating reason for return. 

Additional keys, locks keyed alike or built to code are non refundable as they are personalised made to order goods.

Any refund, which is due to a fault or other defect, will include a refund of the applicable delivery charges otherwise not. 

It is the buyers responsibility to arrange the return of goods to us. We do not offer a collection service for returning items. 

Items must be returned including original product packaging and accessories.

We reserve the right to refuse any returns that do not comply with this policy.

Please post returns to the following address:

Home Secure (Online)

Unit 5, Brookfield Drive

Liverpool, L9 7AJ

United Kingdom

Frequently Asked Questions

An inline espag window lock is a locking mechanism commonly used in uPVC windows. It operates by engaging multiple locking points along the window frame when the handle is turned, improving security and sealing.

The 250mm measurement refers to the length of the espag mechanism. It’s important to match this size with your existing lock to ensure proper fit and function.

Signs include difficulty turning the handle, the window not locking securely, or visible wear on the mechanism. Replacing a faulty espag helps restore smooth operation and security.

Compatibility depends on factors like spindle size, backset, and overall length. Always check your current lock’s specifications before purchasing a replacement.

Selecting the correct mechanism depends on your window type, size, and required security level. To learn more, read: How to Choose the Right Window Mechanism: Friction Stays & Espagnolette