The SD-425 Transmitter can be used as a replacement for a lost transmitter.  You can also use it as an extra transmitter to set two or more transmitters to control the same collar receiver. 

If you already have a SportDOG containment system (SDF-100A) and would like to upgrade it to allow remote training just buy a Contain & Train SDF-CTR Collar Receiver along with this SDT54-13889 handheld transmitter.  The SDF-CTR collar will work with your existing SportDOG containment system to contain your dog, and your SDT54-13889 transmitter will allow for remote training, all with a single contain-n-train collar. How convenient is that!

Note:  Charger NOT included. Look for SAC00-13736 if you need the charger. 

Features

• Reliable signal transmission up to 500 yards-line of sight
• 7 instantly selectable static stimulation levels, Low/medium/high stim ranges, 
• Choose continuous or momentary correction modes
• Choose from stimulation/tone or stimulation/vibrate options 
• Low battery indicator

Transmitter Specs

• Waterproof
• Submersible to 25 feet
• Battery: Fully rechargeable & user replaceable
• Battery Type: Lithium Ion
• Battery Charge Time: 2 Hours
• Battery Run Time: 50-70 Hours per Charge
• Expandable: Yes-up to 3 dogs (requires extra collars, sold separately)
• Transmitter Dimensions With Antenna: 5.30"L X 1.70"W X 1.00"D 

Works With These Remote Training & Fence Collars

• SDR-A
• SDR-AC
• SDR-AF
• SDR-AH
• SDR-AS
• SDR-AW
• SDR-CTR  

Box Includes

• Handheld Transmitter
• Antenna
• Rechargeable Battery
• Lanyard for remote transmitter