See WR741ND too, it is the same HW with removable antenna.

WR740N

is a TP-LINK router with a single non-removable antenna and is the very cheapest in WR series.

Two screws beneath the rear rubber pads are to be removed, for the case to be opened.

WR740N v4.x

The package contains the router, a power supply, a non-removable 5dB omni antenna and an ethernet cable. Since v2.0 there is also a power switch on the router itself, according to a new EU directive.

Note that this router has by default IP 192.168.0.1.

Hardware characteristics

CPU	Atheros AR7240 @ 400 MHz
RAM	32MB
Flash	4MB
LAN	4x 100Mbps Auto MDI/MDIX
WAN	1x 100Mbps Auto MDI/MDIX
WiFi	802.11 b/g/n 150Mbps (130Mbps real) 20dBm - 100mW

Power characteristics

This router is supplied by 9V power supply, durign boot peaks up to 100mA, normal operation 40mA - about 360mW. Total power consumption is greater due to power supply losses adn is about 0.5W.