GPS Warehouse has an own brand version for the 2610
First.. the price is £24.99 plus delivery.
Part No: ANT-19-MCX
Description :Low Profile GPS antenna (MCX 90° connector)
The 'Tekky' bit..
Low profile active GPS antenna suitable for Garmin eMap, GPS76, GPSMAP 76, GPS12CX, GPS12XL, GPS12MAP. Fully waterproof polycarbonate radome enclosure with magnetic base and tapped holes (M3) for screw mount.
Voltage: 2 - 5VDC
Current: 4.5mA
Gain: 19.5dB(typ)
Cable: 5m
Size: (HxWxD) 15 x 48 x 58
RAM-man